The narrator (later revealed to be Mike Hanlon) opens the novel: “The terror, which would not end for another twenty-eight years—if it ever did end—began, so far as I know or can tell, with a boat made from a sheet of newspaper floating down a gutter swollen with rain” (3). The boat belongs to a 6-year-old boy named George Denbrough. His brother Bill—often known as “Stuttering Bill” to bullies, given a speech impediment—made the boat for him at home before letting George go out to play with it in the aftermath of a huge storm. Their mother is playing “Fur Elise” on the piano in the parlor. Four days after the storm began, the water levels begin to drop, and the danger of flooding has diminished.

After folding the boat, Bill sends his brother into the cellar to get paraffin wax to seal the bottom of it. George had always been scared of the cellar and imagines that it's filled with monsters. He goes down the stairs, imagining that “he would hear It, something worse than all the commies and murderers in the world, worse than the Japs, worse than Atilla the Hun, worse than the somethings in a hundred horror movies” (7).